secure my presentations

Kilpailun tehtävänanto

Hi Developers,

I have powerPoint presentation files and vb.net application (VS2012)

the case is my clients will have my powerPoint files and my exe (application) on there pc's

I wan't to secure the powerPoint files by some how so it can't be used/opened/accessed by users, only the application (exe) can use those files
so simply if anyone got the presentation files, he can do nothing with it,

the winner should provide an idea for how to do this and a code(function/class) so I can integrate it with my code and this code must be 100% working fine with my code

of course I don't want solutions like: let's put a password for the powrpoint files and then you provide a vb.net function to open this files (providing the password) as this will simply be hacked by tools which open PP files even if they have password

Wish you all good luck and thank you for participating in this contest,
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Hello All,

I just switched this to guaranteed to show you that I am serious about this,

I hope all of you (which is not rejected) to provide there ideas like #7 entry, as he provide a code (not just talk) and also demo files (which is very important to us) as this allow me to pass the output file from his solution to my friends and challenge them to break it (open it)

for all solutions which depend on steps like (do 1 (encrypt/extract) then use the file then do 2) please provide a solution to the following scenario:
what if the client force close the application after 1 and before 2 ??
what if my application hangs/raise error after 1 and before 2??

please be aware that performance is an important issue for us, so please let me know how much time (if the powerPoint file is 1 MB) your process 1 and 2 will take??

Security come as number 1 then performance

please be aware that the presentation files will need to be added later dynamically so if the client start with 10 presentations then later there must be a simple (programmable) way to add more (apply only to some solutions)
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Any solution which will NOT allow my clients to open any other presentations (not mine) in any time is totally not accepted

Any solution which will allow any one to open my files any time is totally not accepted

My presentation files need to be secured if my exe is exists or not / running or not as simply people can copy past presentation files to other machine (then try to open it there)

Julkinen selvennystaulu

@amrosamaeg, I can build a simple and fast example if you want to test it out. I will make a DLL which you can import in your solution. Then if you want you can even make a GUI around it and just call the appropriate functions.
@chatthusrilanka, if needed by the contest holder I can manage to make a parameter which excepts a array of the changing bits. Then he can choose himself to change whatever he wants. But then again, the implementation I had imagined would not just swap a few bits, but a whole lot of them to change the complete structure.

@BETA911 : My argument is something like this. Say your file is 100KB in size. Let's logically break the file into chunks of 10KB. In other words now you have 10 file chunks.

Now you execute your algorithm on top of this file. And suppose the swapping process changed the bits in 8 chunks but not the other two. In such cases the file recovery utilities can recover data from those two chunks. Especially metadata of file may be retrieved plus perhaps some text from some slides.

To avoid that, you have to change the bits as much as possible. But still smaller chunks exist, so the data is vulnerable. Theoretically you need to change every bit of the file to avoid retrieval of data but the overhead would be high. And you will end up with complicated encrypt/decrypt methods with huge maps.

5 vuotta sitten

Kilpailun järjestäjä

5 vuotta sitten

Dear All,
Can any one open this file??
https://dl.dropboxusercontent.com/u/22964678/Text_Header_Template.pptx

looking forward for your replies All
*specially Mr. BETA911

if anyone was able to open it please give me info about it like how many slides and what is the title of last slide and the title of slide #3 please

Please let me know if you like my idea, to start working on it
and if you have any questions to clarify any thing please ask...

5 vuotta sitten

Kilpailun järjestäjä

5 vuotta sitten

so what if my client run the application then force close it ??
>>and the pp files will be used and not available while the app running<< How?? you said that the application will extract the files while the app is running so anyone can access the files while the app. is running or what ??